The present invention relates generally to vibrator units for wireless communication devices such as radiotelephones.
Today, many wireless devices such as cellular telephones or radiotelephones are small, compact, and portable. Some of these radiotelephones are described as xe2x80x9cpocketxe2x80x9d telephones because they are small enough to fit in the pocket of a user. Unfortunately, as the size of the radiotelephones continues to shrink, the efficient use of space, the numbers and size of components, and the weight of the components can become important design considerations.
Some radiotelephones can operate in a vibrating mode to act as a substantially silent alarm or pager to alert the user. As such, when positioned to contact a user, the vibrating motion can alert the user of a meeting reminder time, an incoming call and the like. The radiotelephone has conventionally provided the vibrator mode by various means. For example, some radiotelephones employ a motor to turn an eccentric weight positioned in the end of the telephone. Other radiotelephones have used a vibration motor which uses centrifugal force to generate vibration. One type of vibration motor is a flat pancake-like motor such as that proposed by U.S. Pat. No. 5,036,239. Another type of vibration motor is a cylindrical motor with a built-in eccentric weight such as that shown in U.S. Pat. No. 5,107,155. Generally described, vibration motors rotate to provide an off-balance distribution of weight and, therefore, a vibrating or even xe2x80x9cbuzzingxe2x80x9d output for the radiotelephone. Unfortunately, these vibrator configurations can be relatively costly due to the number of windings in the motor.
In addition, in the past, the amount of vibration output by the device was typically limited to adjustments to the input frequency, vibrator mass, or displacement of the mass. Increasing the frequency can sometimes cause the vibrating sensation to undesirably produce a sound so as to resemble a buzzing sensation. Increasing the vibrator mass can add weight to radiotelephone which can make it more difficult for the motor to drive, decrease the life of the motor, or increase the size of the motor needed, while increasing the displacement can require the use of additional operational space in a limited space compact design.
There is therefore a need to provide a cost-effective and reliable vibrating unit which can be used with compact radiotelephone designs.
In view of the above, it is an object of the present invention to provide a cost effective vibrator for a compact radiotelephone.
It is another object of the present invention to minimize the number of separate assembly components employed to vibrate the radiotelephone.
It is an additional object of the present invention to provide a relatively non-complex vibrator configuration which includes no rotating eccentric vibrating mass or motor.
These and other objects of the present invention are provided by a miniaturized piezo-ceramic vibratory unit which is configured to vibrate a mass which is a pre-existing component integral to the device. In a first aspect of the invention, a radiotelephone comprises a radiotelephone housing and a battery resiliently mounted to the radiotelephone housing such that it is free to undergo repetitive movement (preferably oscillatory or reciprocal movement) relative thereto. The radiotelephone also includes a vibrator operably associated with the battery. In operation, the vibrator deflects a first direction and a second substantially opposite direction (such as toward and away from the battery) and the battery undergoes repetitive movement relative to the radiotelephone housing responsive to the deflection of the vibrator, thereby providing a vibrating sensation for the radiotelephone. In a preferred embodiment, the vibrator is a piezo-ceramic vibrator. It is also preferred that the radiotelephone includes an electroluminescence (EL) display and a single driver is configured to drive both the piezo-ceramic vibrator and the EL display at a frequency of about 200 Hz (piezo-ceramic vibrator is preferably driven at about 30-200 Hz and the EL display at about 200-500 Hz, thus the dual driver drives at a frequency which is suitable for both).
Another aspect of the present invention is a method of providing a substantially silent alert for a radiotelephone (and/or a wireless communication device). The radiotelephone has a flip or cover, a rotational antenna, a clip, and front and back housing members. The method includes mounting a piezo-ceramic member so that at least one end is fixed to a stationary portion of the radiotelephone. The method also includes mounting a selected radiotelephone component to the radiotelephone so that it is free to undergo repetitive movement in response to contact with the piezo-ceramic member and deflecting the piezo-ceramic member from a non-electrically driven position to an electrically driven position. The selected component is contacted by the deflected piezo-ceramic member and the selected component is repeatedly moved or displaced a distance in a first direction and a distance in a second direction (opposite the first direction). The component translation corresponds to the direction of deflection of the piezo-ceramic member. The selected component has a mass which is sufficiently large with respect to the overall mass of the radiotelephone to generate a user detectable vibration due to the translation thereof. Preferably, the selected component is one or more of the flip, cover, clip, antenna, battery, front, and back housing.
Another aspect of the present invention is method of providing a silent alert for a wireless communication device. The method includes providing a wireless communication device with a vibrating unit which includes a deflecting member and energizing the vibrating unit such that the deflecting member deflects and induces vibratory output for the device.
Another aspect of the present invention is a wireless communication device which includes a wireless communication device housing and a selected or assembly component resiliently mounted to the wireless communication device housing such that it is free to undergo repetitive (preferably reciprocal or oscillatory) movement relative thereto. The device also includes a vibrator operably associated with the selected assembly component. In operation, the vibrator rapidly deflects in a first direction and a second direction substantially opposite the first direction, and the selected assembly component repeatedly moves relative to the wireless communication device housing responsive to the deflection of the vibrator, thereby providing a vibrating sensation for the wireless communication device. Preferably the vibrator is a piezo-ceramic member which is configured as a flat blade like member which is mounted to the housing such that it extends either substantially perpendicular to or parallel to the direction of translation of the selected component. It is also preferred that the selected component is one or more of internally or externally mounted assembly components such as a flip, an antenna, a clip, front housing, back housing, battery, and printed circuit board.